The primary objective of the Clean Water Act (CWA) is to restore and maintain the chemical, physical and biological integrity of the nations’ surface waters. Pollutants regulated under the CWA are classified as either “toxic” pollutants; “conventional” pollutants; such as biochemical oxygen demand (BOD), total suspend solids (TSS), fecal coliform, oil and grease, and pH; or “nonconventional” pollutants, including any pollutant not identified as either conventional or priority. The CWA is implemented via several regulatory programs, including:

National Pollutant Discharge Elimination System Program The CWA regulates both direct and indirect discharges. The National Pollutant Discharge Elimination System (NPDES) program (CWA section 402) controls direct discharges into navigable waters. Direct discharges come from “point sources” which are defined as any “discernible”, confined, and discreet conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fixture, container, rolling stock, concentrated animal feeding operation, landfill leachate collection system, vessel, or other floating craft from which pollutants are or maybe discharged. These include discharges of industrial and municipal wastewater, as well as storm water conveyed through a municipal separate storm water system (MS4).

Combined Sewer Systems Permit Provisions
NPDES permits for municipalities with combined sewer overflow (CSO) must conform to EPA’s CSO control policy. The permitting provisions include minimum technology-based controls that can reduce the prevalence and impacts of CSOs and that are not expected to require significant engineering studies of major construction. Communities with combined sewer systems area also expected to develop long –term CSO control plans that will ultimately provide for full compliance with the VWA, including attainment of water quality standards.

Storm Water Discharges
The storm water program is part of the NPDES program and is designed to regulate the discharge of contaminated storm water (and contaminated discharges from storm sewers that are only supposed to discharge storm water) into navigable waters.

Pretreatment Program
The CWA also requires EPA to promulgate regulations that restrict discharge of wastewater indirectly through sewers to publicly owned treatment (POTWS). POTWs receive wastewater from homes, commercial buildings, and industrial facilities and transport it via a series of pipes, known as a collection system, to treatment facilities. Industrial users of POTWs must comply with CWA pretreatment standards before introducing pollutants into a POTW. These pretreatment standards must control pollutants that may pass through or interfere with POTW treatment processes or contaminate sewage sludge.

Sludge (Biosolid) Management
Section 405 of the CWA regulates the land application and land disposal of sludge- the solid, semisolid or liquid untreated residue generated during the treatment of domestic sewage in a treatment facility.

Spill Prevention, Control, and Countermeasure Plans
CWA Section 311 contains broad federal authority to prevent, respond and cleanup of an oil spill or threat of an oil spill or threat of an oil spill. This provision, as implemented through regulations at 40 CFR Part 112, requires facilities that could reasonably be expected to discharge oil in harmful quantities to navigable waters and adjoining shorelines to prepare and implement Spill Prevention, Control, and Countermeasure (SPCC) Plans.

The Water Quality Standards Program and Tribal Program Approval
Section 518 (e) of the CWA required EPA to issue regulations to specify how the Agency would treat tribes in a manner similar to states for certain CWA programs, including the water quality standards (WQS) program. 40 CFR Part 131 contains the requirements and procedures for EPA to promulgate water quality standards for tribes, for EPA to approve or disapprove tribal applications for treatment as state status to develop EPA-approved for water quality standards.